Many diseases are caused by invading organisms such as bacteria, malaria and worms. In order for these bugs to get inside us and cause disease there is a two-way conversation between our cells and theirs. They are shouting to get in and we are shouting back to keep them out. Much of this conversation is mediated by genes, most of which are not yet known.

We wanted to develop a way to determine which human genes and pathogen genes control this interaction during infection. We looked to see whether we could identify gene pairs that control interaction between the malaria parasite and a mouse. Over the course of infection, we found that genes in the parasite that are used at the same times as in the mouse are often the genes known to be involved in or to control host-parasite interactions.

Remarkably, we found that we could reliably identify many novel pairs of genes involved in host-parasite interactions in malaria. Unlike previous methods to detect these interactions, our approach does not rely on known interactions in other organisms. We found that this method often agrees with previously known interactions, strengthening the reliability of the method. Our approach can generate positive interaction results 70% of the time.

We now have some interesting leads that could help us to better understand how malaria is able to invade its host and cause disease. This is proof-of-principle that looking at how genes of a host and its parasite are used over the course of infection can give us direct insight into which gene pairs are important. More generally we expect that this research will lead to the identification of targets for drug and vaccine therapies.

We are currently exploring this avenue of research further and improving our methods to identify genes that control host-parasite interaction in this way, not only in malaria, but also for diseases caused by parasitic worms.

We expect that this method will allow scientists to discover truly novel interactions and identify entirely new aspects of biology.

Adam Reid is a Postdoctoral Fellow in the Parasite Genomics group led by Matt Berriman at the Wellcome Trust Sanger Institute more…

Research paper

Adam James Reid and Matthew Berriman (2013) Genes involved in host–parasite interactions can be revealed by their correlated expression